I don't really know where to post this thread so I try on the playground.
Since Kushina had the ninetails sealed, does that mean she had it sealed completely?
Minato said that the ninetails is too big to be sealed whole, so he sealed half of it into himself, the other half into naruto.
now, did the uzumaki clan have stronger sealing jutsu to seal the whole kjuubi?
what do you think?
Well, both Kushina and Mito had it sealed when they were older than Naruto. The only thing I can think of is that maybe because Naruto was a baby he woulnd't be able to handle all of the kyuubi's chakra. Kushina taught Minato all the sealing techniques she knew so I doubt it was his technique that didn't allow him to. Maybe this could be but in the official Jinchuuriki thread?
I believe it was implied by Minato that he couldn't seal the whole Kyuubi using the Shiki Fuujin, thus he was forced to only seal half the Kyuubi in the Shinigami. By all accounts, he could have sealed the entire Kyuubi in Naruto had he wanted to.
From what I gathered minato simply did not have the means to fully seal the kyubi. I believe he refered to it as conceptually impossible. I don't know if that was because naruto was too young or because minato didn't have it in him to seal all that chakra into a lone spot. The situation with mito and kushina would have been different for a number of reasons though. Both of them had special chakra's which could for some reason suppress the kyubi. Not to mention they were older. I would think the innate ability they had to supress the kyubi would make a difference one way or the other when it came to sealing the kyubi, specially with the mito circumstances. Minato without any special chakra was able to use uzumaki sealing techniques to seal half the kyubi within naruto. Wouldn't it make sense that the same sealing techniques would be greatly amplified (probably not the best word for it but I think my point is clear) so to speak when a chakra specially capable of controlling the kyubi is used?
I was under the impression it was the same problem as Hiruzen with Orochimaru's soul, not enough chakra to pull out the entire soul in the Shinigami's grip. The fact that the Shinigami comes with his knife means this is bound to happen. All Hiruzen could take with him was two souls and Oro's arms, half of Kyuubi is a huge feat by this standards, and Minato was niticing he was running out of chakra too.
Yeah, I re-read the chapter and it wasn't Naruto's age that effected whether or not Minato was able to seal all of the Kyuubi's chakra inside Naruto. As kkck said, It was just Minato's limitations that prevented him from sealing all of the Kyuubi's chakra even with the Dead Demon Seal. When he said it was impossible, he most likely meant for a non-jinchuuriki/non uzumaki, since both Mito and Kushina were able to contain the entire Kyuubi.